Vista had a few more bugs at launch, but really, there's not a lot of difference between it and Windows 7. It was mostly let down by being too demanding of the hardware available at that time (wow, have I seen Vista run incredibly slowly on some machines), but try running it on a modern PC. By the time Windows 7 was released (with roughly the same system requirements), hardware had caught up both in speed and in driver availability. The Windows 7 lovefest always amuses me given Vista's terrible reputation, considering they're almost the same OS.
I don't find that's the case at all. I had a system that came with Vista. It was certainly under-powered for Vista, with a single-core Athlon 64, 2GB RAM and the slowest 120GB SATA drive on the planet. The system was absolutely horrible. It took forever to boot, and the disk thrashed constantly. When Win7 came out, I upgraded the system [it was free for me through school]. Win7 wasn't exactly a speed demon on the system, but it ran smoothly, and I didn't have to sit there twiddling my thumbs waiting for the disk to stop thrashing every time I clicked the mouse.
Over time, I upgraded the system to a dual-core Athlon64, 4GB RAM and a pair of 10K WD Raptor drives. It ran really really well on Win7. Then for various reason, I tried to go back to Vista on that machine. Even with all the upgrades, the OS was simply unusable. It literally took a solid 3 days of upgrades and reboots just to get it up to SP2. The service packs helped performance a bit, but even with the most current updates, and all the HW upgrades, the system was still slow and unusable.
So I'd say the issues with Vista at launch were not simply an issue of the HW not being up to snuff. No matter the HW, Win7 was far, far more smooth, usable and stable than Vista ever was.